<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			.a {
				width: 0;
				height: 0;
				border-width: 100px;
				border-style: solid;
				border-color: transparent #0099CC transparent transparent;
				transform: rotate(90deg);
				/*顺时针旋转90°*/
			}
		</style>
	</head>
	<body>
		<img title="图片" alt="无图片"  src="./images/bg.jpg" width="100px" height="100px"/>
		<div class="a"></div>
	</body>
</html>
